A statement from Betty Ford said: "My family joins me in sharing the difficult news that Gerald Ford, our beloved husband, father, grandfather and great-grandfather, has passed away at 93 years of age."

The statement did not give the cause of death.

In a message from the White House, President George W Bush said he was "greatly saddened" at the news.

"With his quiet integrity, commonsense and kind instincts, President Ford helped heal our land and restore public confidence in the presidency," Mr Bush said.

"Our 38th president will always have a special place in our nation's memory."

President Reagan's wife Nancy also paid tribute to a "dear friend and close political ally".

"His accomplishments and devotion to our country are vast, and even long after he left the presidency he made it a point to speak out on issues important to us all."

Vietnam War

Gerald Ford was the only US president never to win a national election.

He was chosen as Richard Nixon's vice-president in 1973, when Spiro Agnew resigned amid corruption charges.

Ford succeeded Nixon and brought honesty to the White House

Mr Ford then succeeded to the top office when Nixon became embroiled in Watergate - the scandal over a break-in at the offices of the rival Democratic party in Washington in 1972.

The attempted bugging of the building was linked to officials in the Nixon White House, and the cover-up went all the way to the top.

On taking office Mr Ford declared the "national nightmare" of the Nixon scandal over but soon after he revived the debate by controversially granting his former boss a pardon for any crimes committed as president.

Analysts believe in the short term it may have cost him the 1976 election, but in the long term the decision has been seen as astute.

Mr Ford was in office as the US accepted its defeat in the Vietnam War, with the fall of Saigon in April 1975.

He said it was time to "bind up the nation's wounds".

The opposite of Nixon, Gerald Ford was praised for his openness, sunny disposition and most important, his honesty.

Wife Betty became a national figure in her own right, crusading against drug and alcohol addiction.

Following his stroke, Gerald Ford slipped further from the limelight.

However, he did join Jimmy Carter, George Bush Snr and Bill Clinton at a memorial shortly after the 11 September attacks in 2001.